As the critical dimension of metal oxide semiconductor field effect transistor (MOSFET) devices continues to shrink, the short channel effect becomes more problematic. Fin field effect transistor (FinFET) devices have better control capability of gates than planar MOSFET devices to effectively suppress the short channel effect. Thus, FinFET devices are generally used in the design of small-sized semiconductor devices.
Electrostatic discharge (ESD) is a serious problem for semiconductor devices, especially for FinFET devices that are more susceptible to electrostatic discharge due to the smaller size of the devices.
A diode-type ESD device is a shallow-trench isolation (STI) fin-type diode that forms a PN junction in a fin, and the discharge current flows out the narrow fin. However, in the case where the discharge current is relatively large, the large current flowing through the narrow fin forms local hot spots that cause damage to the fin and reduce the robustness of the diode.